基于DSP的宽动态范围莫尔条纹计数与精密细分技术

摘要

A method of counting and subdivision of Moiré fringe is provided to implement precision displacement measurement. The counting and subdivision of the fringe are completed in DSP (digital signal processor), so it can solve the problem that counting circuit can't match the subdivision system properly by logical judgement. Because of utilizing high-speed optoelectronic converter and flash sample technique, the system can process Moiré signal with wide frequency range. The example demonstrates in the paper can count and divide signals from DC to 1MHz, i.e. If the optical sensitivity of the signal is 1 fringe per μm, the fastest measuring speed can reach 1000mm/s, and the highest resolution is in nm level. The experimental result shows that the software solution has high accuracy and sound reliability.%为莫尔条纹的计数与细分提供了一种基于DSP(数字信号处理器)的高速软件解决方案。它能有效的解决传统系统中计数电路与细分功能不能无缝匹配的问题，提高测量的准确性。由于采用了高速信号处理和闪烁采样技术，采用该方案的系统能处理宽动态范围的莫尔条纹信号。提供的实例能对从直流到1MHz的莫尔条纹信号进行计数与细分，对于1μm光学分辨率的光栅测长系统来说，其相应的最高测量速度为1000mm/s,细分步长可以达到nm级。